Antenna Seanet 2012 Di Panah Petir

Pada 26/11/2012  lebih kurang jam 5.00pm hujan lebat turun di sekitar Kuala Lumpur. Pada ketika itu sedang berlangsungnya Seanet Konvensyen di Dynasty Hotel KL. dan deligasi Seanet sedang dibawa ke tempat-tempat lawatan di sekitar Kuala Lumpur...

Ketika kejadian, penulis berada di tingkat 18 hotel berkenaan, di mana pada masa itu penulis meninjau melalui tingkap..melihat lalu lintas  di jalan Ipoh di mana pada waktu itu hujan turun dengan lebat beberapa saat kemudian berlaku petir dan guruh yang kuat.... pada masa yang sama juga penulis hanya memikirkan bilik radio di tingkat atas bangunan berkenaan.

                                          Antenna Yang Di Pasang di Tingkat Atas Hotel Dynasty

Setelah hujan reda, penulis naik ke tingkat 30 Hotel berkenaan untuk meninjau apa yang sedang berlaku. Di tingkat atas penulis menemui 9M2RDX, 9M2KRZ,9W2SBD, 9W2RUT. Ketika berlaku kejadian petir berkenaan, antenna telah ditanggalkan daripada rig. Menurut mereka, mereka ternampak api...mengalir melalui coax RG213....

                                           Ini lah hasil nya salepas kejadian hujan lebat pada 26/11/12

Di pagi hari, pada 27/11/12 ketika pihak kami ingin menanggalkan tali ikatan daripada tiang antenna Vertical HF yang disediakan oleh 9M2NZ- Maltronic...penulis merenung ke atas dan kelihatan PL 259 sudah tertanggal daripada antenna berkenaan, "Loading Coil" yang dilindungi oleh Plastic PVC dibahagian bawah didapati pecah dan terdapat kesan hitam.....ini mununjukan berlakunya Flash Over/ Surge kepada Vertical Antenna tersebut yang tidak mengalami kecacatan ......Jika antenna tersebut dipanah petir (Hit Directly) sudah pasti kita tak akan jumpa apa2 serpihan...bracket screw dan alluminium tubing dll. Ini berdasarkan pengalaman penulis jika "lightning hit directly" sudah pastinya ia akan hilang di udara manjadi abu dan tidak ada apa yg tinggal ....Alhamdulilah tidak berlaku apa-apa kejadian buruk pada rakan-rakan yang pada ketika itu berada di dalam bilik radio ...itu pun nasib baik tiada siapa yang memegang Coax Kabel....ketika kejadian.....
 

Rakan-rakan yang membantu menurunkan Tri Band Yagi                                    9M2RDX,9M2KRZ,9W2TZ,9W2RUT,9W2SBD









Terima kasih penulis ucapkan kepada rakan-rakan yang mengendalikan bilik radio dan pemasangan antenna  9M2RDX, 9M2KRZ, 9W2SBD, 9W2RUT dll. kepada mereka ini sekali lagi penulis ucapkan ribuan terima kasih pada anda semua.

Kemana Arah Tuju Kita .....

Kemana Kita Salepas ini….

Kita sekarang sudah memasuki 1434Hijrah dan seterus nya ketahun baru 2013…persolan nya kemana kita salepas ini …kemana hala tuju kita ….

Cuba kita fikirkan siapakah yang akan memperjuangkan hak-hak kita sebagai Radio Amatur oleh yang demikian  perlu ada satu badan  yang  perlu memikul tanggungjawab ini.

Apa yang penulis lihat disini ialah banyak persatuan yang tidak mengutarakan masalah yang kita hadapi sekarang ini, bukan nya kelemahan yang kita cari tapi kita perlu menyurakan pendapat kita melalui persatuan atau kelab dan kita semua harus sepakat, carilah  solusi nya….kita perlukan perubahan…..kita harus ciptakan perubahan dan kebaikan.

Penulis kurang faham mengapa masih ada lagi sebahagian dari kita yang berfikiran cetek tidak mahu menerima pembahruan mengapa tidak kita semua bersatu kearah sesuatu yang baik. Salah satu masalah pada orang kita hari ini ialah kita melihat Sape Yang Buat contohnya  jika seseorang itu dia tak suka…apa bende dia buat pun walaupun kebaikan yang dibuat mereka  tak nak ikut sebab dia melihat pada individu tapi jika sekiranya individu itu dia suka walaupun bende yang tak baik dibuat nya individu ini akan menyokong nya… Mengapa tidak kita ubah cara kita berfikir mengapa tidak kita bertindak begini “Tengok apa yang disebut Bukan Tengok Orang Yang Menyebut….”

Lagi satu kenapa kita tidak bersatu…ketepi lah soal peribadi.

“BERSATU KERANA YANG SATU”

Bersatu dalam Masalah…

Kita mesti akui adanya perbezaan pendapat namun….ianya harus berpandukan dengan ilmu dan kefahaman, yang penting disini. Jadilah Ejen Pembahruan ….amalan positif memaparkan akhlak yang baik

“Nilai Diri kita bergantung pada…ketakwaan…….”

Apabila tidak bersatu maka sukar bagi kita untuk berbuat sesuatu………Dari pengalaman penulis.. Apa yang penulis lihat ialah “Kita kurang matang dalam menyelsaikan sesuatu masalah……” Salah satu sebabnya saperti yang penulis sebutkan tadi kita tidak bersatu.

“Apabila kita tidak bersatu hati maka amat sukar bagi kita menyatukan umat…..

Ini semua adalah penyakit  HATI….

Sikap Ego pada diri kita lah yang menyebabkan kita berpecah belah…..masing2 ingin menunjukan siapa yang hebat….tampa merasakan sikap tanggung jawab untuk membantu kearah yang baik demi kebaikan masa depan Radio Amatur. Pada umumnya majoriti dari kalangan kita adalah muslim.....marilah kita sama-sama praktikan apa yang terkandung dalam Al-Quraan.....

Marilah kita menghayati Surah Ali ‘Imran 104-105

Dan hendaklah ada diantara kamu satu golongan yang mengajak kearah kebaikan, menegakan yang makruf  dan mencegah kemungkaran dan mereka adalah golongan yang beroleh kejayaan.

Dan janganlah kamu menjadi saperti orang-orang yang berpecah belah dan berselisih setelah datang kepada mereka keterangan-keterangan yang jelas kepada mereka…….......

RADIO FREQUENCY INTERFERENCE - RFI & THE "WOODPECKER"

The purpose of this writeup is to outline some sources of interference: explain how to eleminate or reduce them and tells you how to protect yourself againts RFI. Remember all cases of RFI involve two things the source of the interference and the victim of the interference.

Generally speaking aside from thunderstorms and lightning static, most interferance is man- made and can be located and suppressed. The problem is finding the source and than applying the remedy. That's not so easy RFI may originate within your own home, within your neighbor's house, from nearby utility lines, or from unknown a thousand kilometers away. Bare in mind RFI problems are found every day as our world becomes more complex and as we invent electronic "black boxes" to perform new task for us.

What does RFI means? Radio frequency interference is a broad term that covers any type of electrical signal capable of being propagated into and interfering with, the proper operation of other electrical or electronic equipment. Another term for RFI is electromagnetic interference (EMI) this latter term is much favored by the military. But both terms, in essence, mean the same thing. As already mentioned RFI can originated in almost anything that uses electricity or that is conected to a power line.

The following is a partial list showing some potential sources of RFI:

Fluorescent lamps and starters

Ignition System

Welding Set

Distribution system

Voltage stabalizer

UPS

Switching Power Supply

Cell Phone Charger

DC to AC Inverters

Computers

Power Lines & Poles

Food Mixers

Hair Dryers

Light Dimmers

Elecrtric Drill

Vacuum cleaners

Motorbikes

Washing machines more and more !

Natural Sources of Interference

Added to the unholy din of man made RFI must be the natural sources of radio noise: static, lightning, atmospheric hiss, radio noise from outer space, and the noise generated by the movement of electrons in the heart of all the elctronic equipment. In short, our world is filled with RFI both natural and man made and as our culture advances, the level will increase-unless something is done about it now.

Noise limit the usefull operating range of all radio equipment. Aside from man made noise, natural radio noise, natural radio noise is all around us. A major source of atmospheric noise (statistic) is a belt of continuous lightning activity around the equator from which interference is propagated toward the rest of the world by ionospheric reflection . Thunder-storms in the temperate zones creat additional radio noise : the overall noise level depends upon frequency, time of day, season of the year and geographical location.

A second sourse of natural interference is galactic noise from outer space. A major generator of galatic noise is the sun and variuos star group have been indentified as radio noise source. Precipitation static is often found in the HF spectrum during a heavy rainstorm, showing up as a loud hiss in the radio receiver or as "snow" on the screen of TV set. It is caused by static electricity building up on trhe receiving antenna. Finally there is a low level of thermal noise in all electrical equipment caused by the thermal agitation of electrons in conductors.

All of these noise sources, plus man made noise, form a "noise floor" in the communication spectrum below which the sesitivity of the communication equipment is restricted. And in a long run, a receiver's ultimate sensitivity, in the absence of man made noise, is determind by natural noise.

The "WOODPECKER"

High Frequency radio communication has been plagued during the past years with an annoying form of man-made interference termed the woodpecker. The interference consists of a series of rapid pulses that ocupy large spectrum. The pulses are extremely powerful and seeming move about at random, knocking out communications over a wide swath frequencies. Examination of the the pulses has led to the conclusion that they are generated by a variable frequency backscater radar system located in the Soviet Union. The purpose of that radar, it is assumed, is to detect the launch of intercontinental ballastic missiles.The system seems to have two transmitters located in the Ukraineand Siberia that transmit pulses over the North Pole towrds the United States. The reflected pulses provide information on ionized trails left by the launch of a surface missile.At present the woodpecker have not heard through the HF spectrum. We never know what will happen next.

An RF Noise Source - The Spack Discharge

A partial list of equipment capable of creating RFI, particularly of the Spack discharge type is given above. You can think of other devices which fit this category.In addition to the spack discharge, there are two other classes of RF noise generators : the electrostatic discharge and the RF oscillator. Radio transmitters are included in this last class. Each class of noise has its own pecularities and leave its own unique "noise print" a fact that is helpfull in tracking down the source. Lets examine these sources starting with spark discharge which is common to all neighborhoods. A natural discharge is a lightning stroke. A good example of usefull spark discharge is the ignition system and spark plugs in gasoline motor.

The charecteristic sound associated with spark discharge may variously be describe as a buzzing rasping, popping noise similar to bacon frying in a pan. Spark discharge seen on the TV screen appears as a band of horizontal dot-dash

Ok nows lets look into how to cure the noise.

Ok example if you install your VHF/HF rig inside your car. There is no problem when the engine is off. But if you have a problems when your engine is on example the receiver will pickup a noise wiiiigg.....wingggg....and its becomes louder if you press your excelerator. Check all the connections tighten all the connections at the battery terminals, your lines fuse..supply together with your VHF rig. And if the noice is still there its time to service your alternator the carbon brush at the alternator maybe needs to be replace or your alternator needs to be service. If you have a problem when you turn on your Air Cond in your car what you can do is just install a capacitor 0.001uF at the Condenser Fan which is located near your Radiator.

                                   Ignition type capacitor/condenser

For those who works from base station make sure you have a good grounding system and avoid using a cheap type switching power supply. You may also install a line filter at your AC line. If you have space you can install a QUAD or a LOOP antenna this will help you to reduce the noise level.

                                           AC LINES FILTER